MCP & Protocols2026-04-17•396 words•2 min read

A2A + MCP Layered Architecture Pattern (InfoQ, Feb 2026)

#mcp#security#llm#coordination

A2A + MCP Layered Architecture Pattern (InfoQ, Feb 2026)

Source: InfoQ - "Architecting Agentic MLOps: a Layered Protocol Strategy with A2A and MCP"

Published: February 2026

Author: InfoQ Technical Article

Core Pattern

A2A + MCP Layered Architecture:

A2A = Communication bus for agent-to-agent coordination

MCP = Universal language for tool/data capabilities

Together = Robust, scalable, extensible multi-agent systems

Key Takeaways

Decoupling Principle: Layered architecture decouples orchestration logic from execution logic

Extensibility: New capabilities can be added without changing core communication logic

Evolution: Move from rigid monolithic systems to agile agent-driven operations

Reusability: Pattern works across any domain, not just MLOps

Protocol Roles

A2A (Agent-to-Agent)

Agent Cards: Describe capabilities, protocols, request types

Discovery: Agents find each other without hard-coded connections

Communication: JSON-RPC over HTTP/SSE

Governance: Linux Foundation (neutral, collaborative)

Why it matters:

Turns isolated "single-shot LLM tools" into multi-agent systems

Enables peer-to-peer agent calls, not just API client relationships

Supports horizontal scaling of intelligence

MCP (Model Context Protocol)

Tools: Actions agents can invoke (execute code, call APIs)

Resources: Structured data agents can query

Prompts: Predefined templates for agent behavior

Security risks: Prompt injection, tool poisoning, unauthorized data access

Security enhancement: MCPWatch for system protection

MLOps Example Architecture

Orchestrator Agent (A2A coordinator)
├── Validation Agent (A2A specialist)
│   └── MCP tools: fetch_model, validate_churn_model
└── Deployment Agent (A2A specialist)
    └── MCP tools: deploy_model, verify_deployment

Flow:

Orchestrator receives high-level query

Uses LLM to break into TaskList of sub-goals

Discovers appropriate specialist via A2A

Specialist creates tool-use plan via MCP

Results stream back through hierarchy

Connection to UCP

Universal Commerce Protocol (Jan 2026) combines MCP + A2A + Agent Payments Protocol. This layered pattern is now industry-standard for agentic systems.